Geography
According to the U.S. Census Bureau, the county has a total area of 1,671 km² (645 mi²). 1,576 km² (609 mi²) of it is land and 95 km² (37 mi²) of it is water. The total area is 5.66% water.

Demographics
As of the census of 2000, there are 22,644 people, 8,590 households, and 6,133 families residing in the county. The population density is 14/km² (37/mi²). There are 9,821 housing units at an average density of 6/km² (16/mi²). The racial makeup of the county is 97.35% White, 0.19% African American, 0.18% Native American, 0.40% Asian, 0.00% Pacific Islander, 1.40% from other races, and 0.48% from two or more races. 2.15% of the population are Hispanic or Latino of any race.

There are 8,590 households out of which 33.70% have children under the age of 18 living with them, 61.50% are married couples living together, 6.30% have a female householder with no husband present, and 28.60% are non-families. 24.40% of all households are made up of individuals and 12.00% have someone living alone who is 65 years of age or older. The average household size is 2.58 and the average family size is 3.07.

In the county the population is spread out with 27.00% under the age of 18, 7.40% from 18 to 24, 26.40% from 25 to 44, 23.00% from 45 to 64, and 16.30% who are 65 years of age or older. The median age is 38 years. For every 100 females there are 101.70 males. For every 100 females age 18 and over, there are 98.90 males.

The median income for a household in the county is $40,908, and the median income for a family is $47,923. Males have a median income of $33,157 versus $22,743 for females. The per capita income for the county is $18,628. 7.10% of the population and 4.70% of families are below the poverty line. Out of the total people living in poverty, 6.40% are under the age of 18 and 13.80% are 65 or older.